Protector for telegraphic and telephonic instruments



(No Model.) 2 SheetR-Sheet 1.' M. D. OONNOLLY.

PROTECTOR FOR TELEGRAPHIO AND TBLEPHONIG INSTRUMENTS. No. 279,714.Patented June 19,1883.

WITNESSES INVENTOR ATTORNEYS (No Model.) I 2 Sheets-Sheet 2. M. D.CONNOLLY.

4 PROTECTOR FOR TELEGRAPHIU AND TELEPHONIG INSTRUMENTS7 No. 279,714.Patented June 19,1883..

" WITNESSES If INVENTOR a; flfigfiv,

ATTORNEYS N, PETERS, Photo-Lilbcgruphur.-Wash|n5mn, 11c

UNITED STATES PATENT OFFICE.

M. DANIEL ooNNoLLY, or PHILADELPHTA, PENNSYLVANIA.

PROTECTOR FOR TELEGRAPHIC AND TELEPHONIC INSTRUMENTS.

SPECIFICATION forming part of Letters Patent No. 279,714, dated June 19,1883.

Application filed February 16, 1883.

T0 aZZ whom, it Hui/y concern Be it known that I, M. DANL. CoNNoLLY, acitizen of the United States, residing at Philadelphia, in the county ofPhiladelphia and State of Pennsylvania, have iiwented certain new anduseful Improvements in Protectors for Telegraphic, Telephonic, and otherElectrical lnstruments;.and I do hereby declare the following to be..afull, clear, and exact descrip tion ofthe invention, such as will enableothers skilled in the art to which itv pertains to make and use it,reference being had to the accompanying drawings, which form part ofthis specification, in which- Figure 1 is a perspective; Fig. 2, a sideView, showing a modified mechanical construction; and Fig. 3, a diagram.

My invention has relation to devices for diverting harmful electricalcurrents from telegraphic, telephonic, and other electrical instruments,and my improvements have for their object to protect such instruments onboth their sides, as hereinafter fully described, by means of a singleprotectorthat is to say, without using two protectors, one on each sideof the protected instrument.

My invention consists in the peculiar construction and combinations ofparts hereinafter fully described, constituting the protecting device,and in the combination therewith of a telephone or other electricalinstrument within the circuit of the protecting device;

For the diversion of abnormal currents I have previously invented adevice comprising an electro-magnet with armature in circuit therewithand making circuit alternately to line an d ground, to line normallywhen the armature was unattracted, and to ground when attractionoccurred through the influence of such abnormal currents. Such devicehas been found to answer admirably for the ends of a line, or wherecircuit is made directly to earth from the instrument protected; butsaid protector was not designed'for a case where the earth is not madedirect and the line proceeds onwardas, for example, where severaltelephone-exchange subscribers have their in struments placed on one andthe same line.

My present improvements have for their 0bject to provide a protector forthe case just suggested-that is to say, a device which will (N0 modelhprotect telephone or other instruments on both sides, or on what may becalled its incoming or outgoing lines.

Referring-to the accompanying drawings, A represents an electro-magnetor solenoid comprising two helices, and (1, the latter being woundoutside the former. Bis the armature of said magnet, having aretracting-spring, C, and front and back stops, D E, respectively. Fromthe front stop, I), there is a line, 1, to. earth or metallic return,and from back stop, E, circuit is made to the telephone or other in--strument F to be protected. Circuit is as follows: Main line 2 proceedsfirst to inner helix, (1, thence to armature B, and from latter, whileretracted, by back stop, E, to telephone or other instrument F. Frominstrument F circuit is by line 3 to outer helix, a, and thence by mainline 4 onward. A normal or ordinary working current in either directiontakes the path indicated. There is a branch line, 5, leading off fromline 3 at acto a spring, G, which stands between the armatureB and frontstop, 0, but does not, in the normal posture of 7 5 affairs, makeelectrical contact with either of said parts. Consequently circuit byway ofGis normally open; but let an abnormal current get onto line. saybyacross of an electric-light line at y said current passes throughhelix (1, energizing the same, and causing armature B to be attractedaway fromE and toward D. This breaks line to instrument F, and makescircuit to ground or metallic return by way of line 1. The instrument F,being cut out, is protected against the abnormal current which obtainsaccess to line on that side of the instrument which pertains to line 2or cross y. Suppose, again, an abnormal current gets onto line on theother side of the instrument-say by an electric-light line making across at Z said 'current first traverses outer helix, (6, energizing thesame, and drawing up armature B, making contact with spring G, andbinding latter against front stop, D. This closes circuit through lines3 5 l to ground or return and cuts out instrument F. The said instrumentis thus protected against such abnormal current, and the latter, so longas it continues flowing, maintains the energization of helix a, andfinds a short course to earth or to return from 2 by way of line 5,spring G, front stop,

D, and line 1. It will thus be seen that no matter on which side oftheinstrumentF an abnormal current gets onto line said instrument iscompletely protected, and that when the normal or ordinary workingcondition of parts prevails, sai d instrument in a circuit within theprotector, or is in the protectors internal circuit. \Vheu the abnormalcurrent is very powerful, the initial impulse or attraction of thearmature is sufiicient to draw the latter far enough to close thecontacts I) G, in which case no vibration of the armature takes place.If desired, however, a spring may be located in the place of the stop E,so as to continue the circuit therethrengh until the armature hasacquired momentum enough to fully insure a complete est: blishment ofthe earth-ci1= cuit. It is, however, considered advantageous to omitthis spring when it can be done, in order to avoid the formation of anelectric are between it and the armature]ever.

\Vhat I claim as my invention is as follows:

1. A device l'or protecting telegraphic, telephonic, and other eleetrical instruments against abnormal currents o't' electricity, or fordiverting such currents fromelectrical instruments, comprising anelectro-magnet, A, having two helices, (t and(l/, an armature, 3, withfront and back stops, 1) E, respectively, a spring or contact piece, G,norn'lally out of circuit, said stop I) being connected to ground, andthe spring or contact piece (1- being located between the armatureleverand the steps I) G, and connections for said parts, substantially asshown and described.

2. An elochre-magnetic protector for electric instruments, comprising anelectro-magnet, ground and line stops, and devices, substanti ally asdescribed, whereby al'mormal en 1'- rents from. either side of theinstrument are diverted therefrom to ground, as set forth.

In testimony that I claim the foregoing l have hereunto set my hand this15th day of February, .l 883.

M. DANIJ. ("(WXXOLIJY \Yitnes;

.l'os. l3. CONNOLLY, \VM. I-I. Pownim.

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